GASTRIC TUBULES. 213 



former are supposed to secrete the gastric juice and are ac- 

 tive only during digestion, while the latter secrete a glairy 

 mucus, which is not produced specially during digestion and 

 which has no distinct digestive function with which we are 

 acquainted. 



Gastric Tubules. These are the organs , sometimes de- 

 scribed under the name of peptic glands, or stomach-glands. 

 In the large middle zone of the stomach, the tubes are simple, 

 extending through the entire thickness of the mucous mem- 

 brane. Their average length is about ^ of ari inch, and 

 their diameter is from T i to -3 of an inch. They are com- 

 posed of a delicate, structureless, basement membrane, with 

 the upper fourth or fifth lined with a continuation of the 

 general columnar epithelial covering of the stomach, and the 

 lower portion filled with, rather than lined by, hexagonal, 

 soft, secreting cells, called the stomach or peptic cells. These 

 cells have a nucleus and nucleolus, contain numerous 

 rather large oval granules, and are about T ^Vo- of an inch 

 in diameter. This is the general character of the tubes over 

 the greater part of that portion of the mucous membrane 

 which secretes the gastric juice. These tubes readily un- 

 dergo post-mortem alteration, and, in the human subject, 

 are only to be seen satisfactorily in the fresh stomachs of sub- 

 jects who have died suddenly, having previously been in a 

 condition of perfect health. 



Around the cardiac opening of the stomach, are compound 

 tubes, composed of essentially the same anatomical elements 

 as the simple tubes, and undoubtedly endowed with the 

 same function. 1 These commence by a short tube, or duct, 



1 Tubes of this kind are described and figured by Kolliker (Manual of Hu- 

 man Microscopic Anatomy, London, 1860, p. 320); but Sappey (Traite tfAna- 

 tomie Descriptive, Paris, 1857, tome iii., p. 120) attributes this to an illusive ap- 

 pearance produced by a super-position of different tubes, and asserts that such 

 glands certainly do not exist in man. The appearances described by Kolliker 

 have been often found by other observers, and there can be little doubt that 

 compound follicles exist just around the cardia ; but they probably are not found 

 in other parts of the mucous membrane. 



